Layout data for PageBuilder is stored in the WordPress postmeta table in a serialized array.
Live PageBuilder data is stored using the postmeta key _fl_builder_data, , while draft data is stored using the postmeta key _fl_builder_draft.
When you activate PageBuilder, any content that is already in the WordPress editor is migrated to a text module within PageBuilder. In addition, every time you make changes and publish a PageBuilder layout, a stripped-down version of the layout is saved to the WordPress editor so your content is available should you ever decide to deactivate PageBuilder.